Windows 10 Gets Critical Security Update to Fix Outdated Certificates
Microsoft has released a critical security update for Windows 10 versions 22H2 and 21H2, as well as Windows 10 Enterprise LTSC 2021 and Windows 10 IoT Enterprise LTSC 2021. The update, KB5120249, focuses on security rather than new features and addresses outdated Secure Boot certificates.
The roughly 1GB update also resolves File History errors, improves Microsoft Defender, and includes fixes for the Windows Malicious Software Removal Tool. This is the next entry in Windows 10's Extended Security Updates program, which ensures that users can continue to receive security updates until at least October 2027.
Users must enroll in the ESU program to receive continued protection after standard Windows 10 support ended in October 2025. The update includes additional high confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates.
The update also updates Defender, the .NET Framework, and the Windows Malicious Software Removal Tool. Users can download the update manually via the Microsoft Update Catalog or wait for it to be installed automatically by Windows 10 once it's available.